Remove unused parts of IPC::ChannelHandle.

android_webview/browser/aw_printing_message_filter.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "android_webview/browser/aw_printing_message_filter.h"
 
 #include "android_webview/browser/aw_print_manager.h"
+#include "base/file_descriptor_posix.h"
 #include "components/printing/common/print_messages.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/render_view_host.h"
 #include "content/public/browser/web_contents.h"
 
 using content::BrowserThread;
 using content::WebContents;
 
 namespace android_webview {
 
@@ skipping 60 matching lines @@
     int render_view_id,
     int sequence_number) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   AwPrintManager* print_manager =
       GetPrintManager(render_process_id_, render_view_id);
   if (print_manager)
     print_manager->PdfWritingDone(true);
 }
 
 }  // namespace android_webview